Air brake safety device



March 5, 1935. c. c. BRUNER AIR BRAKE SAFETY DEVICE Original Filed Sept. 5, 1930 Patented Mar. 5, 1935 UNITED STATESPATENTOFFICEV' is 1,993,239 Ant BRAKE 'SAFETYDEVICE Clarence C. Brunenlhippsburg, Colo. V

Application september 5, 1930, Serial No. 480,002 x Renewed January 21, 1935 r 3 Claims. (Cl. 3 03-77) 'This invention relatesto improvements in air brakes, and more particularly to asafety auxiliary reservoir of each car to the brake cylinder thereof. v

During the operation of railroad trains particularly down relatively steep or long grades, it is necessary that continual and successive re duction in pressure be made in the train-line in order that a proper air pressure within the brake cylinders may be maintained, from the auxiliary reservoirs, to compensate for leakage therefrom; Through these successivereductions the pressure in the auxiliary reservoirs becomes so far depleted within a relatively short time as to become ineffective. In like' manner' when a full service application ismade, any further leakage of air would 'di'aw'from or decrease pressure in both the auxiliary reservoirs and brake cylinders, thus decreasing any braking a pressure.

It is therefore essential to provide some'means for restoring proper pressures'withih" both the brake cylinders and the auxiliaryreservoirs, either when the'pressure in the said reservoirs has'been'reduced to below'a certain quantity or to a dangerpoint, or when a full service application of brakes be made. It is accordingly a"major purpose of the present invention to provide in air brake systems of the class set forth; a novel safety device for insuring the restoring or replenishing of air pressure Within the'auxiliary reservoirs when the same shall have been reduced to below a danger point; and to recharge the train-line when so required without releasing of the brakecylinder pressure. It is a further object of the present invention to provide in an brake systems of the class set forth, a novel retaining device or valve which will insure the maintaining of any set or de- 50 sired pressure within the rake-cylinders, and

the constant maintaining of proper and adequate pressure within the auxiliary reservoirs. A still further object of the invention is to provide a novel safety retaining valve ofthe class lseat l separating the two bores.

set forth whereby a greater flexibility of range of brake cylinder settings may be had to compensate either for the continually. increasing Weights of railroad cars, particularly freight cars, and the. consequent variation of trainweight with the cars either loaded or empty. Further objects'of the invention will be herein after more fully set forth.

The accompanying drawing illustrates one practical retaining device of the class set forth, constructed. .in accordance with the presentin vention, which will be described in detail to enable others to understand and use the 'same,- but the invention is not considered restricted to the specific construction shown in the drawing, and reference is therefore had to the claims for summaries of the essentials of the inventionand of the novel featuresof constructionand of the novel combinations-of parts for tection is desired. j

In the drawing: I

vFigure 1 is a central vertical sectional view taken through the entire novel retaining device,

illustrating the operative parts thereof in position when av suiiicient reduction is made to maintain a set brakingv pressure.

Figure 2 is a detail horizontal sectional view taken on the line'2-2 of Figure 1. I Figure 3 is a detail horizontal sectional takenonthe line 3-3. of Figure 1. Y I

As shown in the drawing, the novel retaining valve which may be of any desired size and View conformation, comprises a substantially tubular casing or housing 1, provided at its upper-extremity with an annular shoulder adapted for all of which proa able apertures are provided for the passageof 7 securing devices of any desired character such as bolts or the like 2 The casing 1 is provided at its lower extremity with a threaded aperture 1*, for engagement or connection to the train-line (not shown) the casing further including an interior bore 1 pro- The bore 19 is vertically disposedand communicates atits upper extre'mitywith an enlarged bore 1 anangularly disposedconical valve The bore. i in turn c'o'mmunicates -at its upper extremity with a stillfurther'ehlarged bore-1 extending to the top of the casing and for a purpose tobe hereinafter more fully described. A threaded aperture 1 is provided extending through aside wall of the easing into the bore 1, thus providing communication therebetween and an auxiliary reservoir (not shown); the casing being further provided with a second threaded aperture l also horizontally disposed through a side wall thereof to communicate with the bore 1 at a point immediately above .the valve seat 1 to provide communication between this portion of the bore of the casing and the usual train pipe connection of the triple valve (also not shown).

A conical valve 3, adapted to seat upon the valve seat 1 is disposed within the .bore 1 of the casing, the said valve including a stem 3 having a guide portion 3 thereon adapted to guide the vertical reciprocation of the said valve. Preferably the valve stem 3* has integrally formed on the upper extremity thereof a piston 3 provided with the usual piston rings 3 adapted to engage against the walls of the. bore or cylinder i The piston 3 is provided on theupper surfacethereof with a recess 3 adapted for the reception of a relief valve 4 of conical conformation; therecess 3 being threaded for engagement with the relief valve body a Preferably this relief valve body includes an interior bore 4, and is provided at its lower extremity with a conical -valve seat 4 against which the valve 4 is adapted to seat. It will be noted that both the valve guide 3' and the bottom wall of the piston 3 are provided with an aperture or port 3 to permit of the passage of air romthe train-line so as to close the ,valve 4 upon the opening of the valve 3, for a purpose to be hereinafter more fully described. I

The relief valve 4 further includes a winged stem portion 4 adapted to fit freely within the bore 4 -..Any desiredmeans might be provided to impart a propertension to the valve 4., Preferably such means are resilient and include a coil spring 4 positioned within the bore 4 and adapted to bear against the top of the valve stem.

The bore 4* is threaded at its upper extremity for engagement with' a similarly externally threaded adjustingscrew i for governing or varying the spring pressure against the valve 4.

A look nut 4 might be provided forinsuring the 7 locking of the screw 4 for any desired adjusted position or setting'of the valve.

Preferably the cylinder head 2 includes a reduced vertically disposed tubular portion 2 adapted to surround the upper portion ofthe relief valve body, and further adapted to house adjustable means forcontrolling the pressure or tension upon the main Valve .3. Such means might well. be similar to the above described means for adjusting the relief valve pressure, including a coil spring or the like 2 adapted to bear against the upper surface of the relief valve housing, and adjusting screw 2 being threaded within the upper extremity of the tubular. portion 2 of the cylinder head, and adapted toengage against the spring 2 ,the said screw .being provided with a lock nut 2 for maintaining the same locked in any desired set or adjusted position.

The connection 5 bet'weenthe casing 1 andthe triple valve is of any desired convenient construction as is known in this'art, and is accordingly believed to require no particular'discussion here. A suitable connection is provided between the casing l and the auxiliary reservoir. Preferably such connection includes a threaded nipple 7 adapted for engagement with the threaded aperture 1 of the casing. a

The nipple '7 is provided with an interior bore '7 including a conical valve seat 7 upon which quired tensions at which it a suitable check valve 8 is adapted to seat. Preferably the check valve 8 may include a piston ring 8* adapted for engagement with an enlarged portion I? of the bore '7; a groove or the like 7 bethreaded aperture for engagement with a suitable pipe-line 9 leading to the auxiliary reservoir (not shown).

' In the operation of the herein described safety device, the several valve adjusting means are properly set in the assembly thereof at the reis desired that they operate.

The following example of operation is given for the purposeof. explanation only and it is to be understood that all adjustments may be changed to meet requirements. With brakesystem of the train at atmospheric pressure, spring 2 set at 90 pounds, spring 4 set at 50 pounds, and spring 8 set at 50 pounds, the train line feed valve set at 70 pounds, the automatic brake valve is placed in full release position to charge said system.

' When the train line pressure exceeds 50 pounds, spring 8 will open and permit a small amount of air to pass to the auxiliary reservoir and will close when the auxiliary reservoir is charged. When the train line pressure reaches 90 pounds, spring 2 will be compressed and valve 3 will open and permit free communication between the train line and the triple valve through I Air passing through'port 3 will close valve 4 by compressing spring 4 the flow through said port being relatively rapid. The train line and auxiliary reservoirs may then be charged, operated and tested in the regular manner.

' In ordinaryservice operations my device does not operate for the following reason: The large area of piston 3 enables 50 pounds of air pressure to hold spring 2 compressed.

The only time the device is intended to operate is when the train linepressure is drawn down to a dahger'point, 50 pounds for example. This-condition would arise while descending heavy grades as the result of successive brake applications. At this point spring 4 opens valve 4 and spring 2 closes valve 3. It will now require 90 pounds of air pressure on valve 3 to release the brakes in full. However air pressure may be applied to the brake cylinders through the auxiliary reservoirs and triple valves through valve 8 and pipe 9 as needed, by increasing train line pressure. It is believed that the above explanation shows .how the device will retain, replenish or release of the retaining valve returned to normal running position by increasing the train line pressure to a point exceeding the pressure of the adjusted spring 2 when the valve 3 will open.

It is to be understood that wherever in the foregoing description the terms air or air pressure have been employed, that the present invention will operate fully as satisfactorily with any other desire type of fluid pressure.

There has thus been described a novel safety retaining device adapted for use in connection with air brake systems of the class set forth, which will insure the maintaining of any desired set pressure Within the brake cylinders and the constant maintaining of proper and adequate pressure within the auxiliary reservoirs, and which will further insure, the recharging of the trainline when so required without thereleasing of the brake cylinder pressure. 7 p

The invention having thus been described what is claimed is:-

1. In an air brake system, the combination with a train-line, auxiliary reservoir, triple valve and brake cylinder, of a retaining valve comprising a casing provided with a vertical bore, a valve seat in said bore, an adjustable vertically disposed main valve adapted to seat thereon and operable by train-line pressure, a'piston carried on the upper extremity of the said valve, an adjustable relief valve housed in the-said piston, means for supplying fluid pressure upon the relief valve to maintain the same closed when the main valve is opened and means for opening said relief valve upon reduction of the fluid pressure.

2. In an air brake system, the combination with a train-line, auxiliary reservoir, triple valve and brake cylinder, of a retaining valve comprising a casing having a vertical bore therein,-, a valve seat in said bore, an adjustablevertically disoperable by train-line pressure, a piston carried onthe upper extremity of the said valve and engaging with an enlarged portion of the said bore, an adjustable relief valve housed in the said piston, means for varying the tensions of both the main valve and the relief valve, means for supplying fluid pressure upon the relief valve to maintain the same closedwhen the main valve is opened, means for opening the relief 'valve upon reduction of the fluid pressure, a connection hetweenthe casing and the auxiliary reservoir below the main valve seat, and an adjustable check v valve in said connection.

3. In a safety retaining devicejof the'class set forth, in combination, a casing having an interior bore therein, a valve seat in said bore, a vertically disposed valve adapted to seat thereon the said valve includinga piston on its upper extremity engaging Within anfenlarged portionbf 'thesaid bore, a recess in the hea'd' of said piston, a housing engaging inthe recess the said housing including a valve seat, a relief valve adapted for engagement with said seat, means for adjusting the tension of both the relief valve and the main valve, a connection above the main valve between the casing and the triple valve, connection below the main valve between the casing and the auxiliary reservoir, an adjustable check'valve in :said a last mentioned connection, means for supplying fluid pressure to the casing whereby. to open the main valve and supply pressure to the triple valve,

means for supplying pressure to therelief valve to maintain the same closed whenfthe main valve is opened said means comprising a port in the aforementioned piston, andmeans for opening the relief valve and closing the main valve upon reduction of the fluidpressure. g

' CLARENCE C. BRUNER. 

